In an effort to simplify and quicken final vehicle assembly and service, attention has been directed to the modular construction of a motor vehicle including those with a foot operated clutch that drivingly connects the engine to a manual transmission. Typically, the clutch assembly is bolted to the rear face of a flywheel connected to the engine crankshaft and these components are covered by a bell housing that is bolted to the engine block. To service the clutch one must then reverse this assembly to gain access to replace parts or make an internal adjustment such as to compensate for wear in the clutch. U.S. Pat. No. 5,238,093 is an example of such piece meal assemblies and wherein manual adjustment is provided to relocate a diaphragm spring and pressure plate to compensate for wear. While the clamping force and release effort is maintained by this adjustable arrangement, the pedal travel is increased unless compensated for in the linkage to the clutch pedal. Various modular constructions have been proposed as well as various provisions for automatic wear adjustment within the clutch assembly itself. But these efforts have fallen short either in providing less than a full modular package and/or in not being able to include an adjusting arrangement that will automatically maintain the desired clutch pedal effort and travel as well as the desired clutch apply force as wear occurs.
For example, U.S. Pat. No. 5,191,810 discloses a modular form of construction but excludes both the flywheel and any automatic wear adjustment. U.S. Pat. No. 4,339,023 likewise excludes the flywheel but does have automatic wear adjustment for a twin plate clutch using a plethora of independent multi-spring biased tapered devices. These devices relocate only one of two pressure plates; i.e. the one that is sandwiched by the two driven plates, to maintain clearance wherein the clamping force will decrease and the pedal effort and travel will increase with such wear adjustment. U.S. Pat. No. 4,684,002 discloses a similar manner of wear adjustment in a twin clutch using different adjusting devices that have the same shortcomings. U.S. Pat. No. 4,832,164 does disclose automatic wear adjustment wherein the pressure plate and spring assembly are relocated to compensate for wear but the pedal travel is thereby increased. This arrangement like that in the above U.S. Pat. No. 5,238,093 is not suited for a modular construction of the entire clutch assembly including the flywheel.